| Background:MicroRNAs (miRNAs) are endogenous noncoding RNA molecules of approximately22nucleotides in length that play important regulatory roles in metabolism, cell signaling, function, decay, migration, apoptosis, dedifferentiation and transdifferentiation by targeting the cleavage or translational repression activitiesof mRNAs. Recent studies have found that many of miRNA specific expression in skeletal or cardiac muscle. These miRNA are called muscle miRNA groups.The miR-1/miR-206and miR-133a families are the most extensively studied myogenic miRNAs. However, no study has addressed whether mature miRNA mimics can promote myoblast differentiation. In this study, we attempted to decipher the biological function of these tree miRNAs in the differentiation of C2C12cells.Method:qRT-PCR verification of miR-1, miR-133a, miR-206, miR-1-206, miR-1-133a, miR-133a-206mimic transfection of C2C12cell48hours, the expression change of muscle related genes. We observe the myotube fusion and calculate the fusion rate after miRNA-1, miRNA-133a, miRNA-206, miR-1-206,miR-1-133a, miR-133a-206mimic was transfected into C2C12cells for5days. Expression of MyHC protein was detected by immunofluorescence assay.Prediction of miR-133a target genes:Using software Target scan, MICRORNA and PicTar to predicted the target gene of miR-133a. And construction of pMIR-REPORT fluorescent reporter vector to verified the target gene.qRT-PCR testing the expression changes of miRNAs and Foxl2gene after C2C12differentiation by the2%horse serum for five days. Observing the myogenic differentiation of C2C12after Fox12was knockdown by siRNA.Result:The results show that directly transfecting mature miR-133a, miR-1/206, or combinations (miR-1and miR-206; miR-1and miR-133a; miR-133a and miR-206) into C2C12cells respectively for5days induces formation of myogenic progenitor cells. Overexpression of miR-133a and miR-206in C2C12cells greatly improved multinucleated myotube formation. Foxl2was identified as a targeted of the miR-133a. The targeting of Foxl2also shows promise, but further study is needed to elucidate how miR-133a influences differentiation through Foxl2gene. The miRNAs characterized in this work have potential therapeutic applications and may be useful for identifying other targets for treating muscle diseases. Since this differentiation approach does not require vector-based gene transfer and leaves no residual vector DNA, it holds significant potential for biomedical research and regenerative medicine.Conclusion:1. The mature miR-133a, miR-1/206, and the combinations miR-1-133a, miR-1-206and miR-133a-206can differentiate C2C12cells into muscle precursor cells.2. The miR-133a-206can greatly improve the formation of C2C12cell differentiation in multinucleated myotubes.3.3’UTR of Foxl2is the targeting site of miR-133a. Recently, genome-wide associated studies (GWAS) have identified that host genetics IL-28B SNPs rs12979860and rs8099917were significantly associated with SVR in patients infected with chronic HCV genotype1to PEG-INF/RBV therapy. Results from these studies remain conflicting. We conducted this meta-analysis to estimate the overall association of SVR with rs12979860and rs8099917. We searched the PubMed, Embase, Scholar Google, ISI Web of Knowledge, and Chinese National Knowledge Infrastructure (CNKI) databases for all articles before July30,2012. The odds ratio (OR) corresponding to the95%confidence interval (CI) was used to assess the association. The statistical heterogeneity among studies was assessed with the12statistics. Begg’s test and Egger’s test were performed to evaluate the publication bias. Eventually, twenty studies were selected for the meta-analysis. The IL-28B SNPs rs12979860genotype CC and rs8099917genotype TT significantly positive associated with SVR in patients infected chronic HCV genotype1to PEG-INF/RBV therapy (OR=4.473,95%CI=3.814-5.246, OR=5.171,95%CI=4.372-6.117respectively). The results suggested that rs12979860genotype CC and rs8099917genotype TT could be used as independent predictors of the HCV-1infected patients.Meanwhile, we also conduct a systematic review of group studies assessing the association of serum vitamin D status with the severity of liver fibrosis in chronic hepatitis C patients. The relevant research literatures were identified by searching PubMed, EMBASE databases prior to October2013with no restrictions. We included group studies that reported odds ratio (OR) estimates with95%confidence intervals (CIs) or a mean with standard deviation (SD) for the association between serum vitamin D status and the severity of liver fibrosis in chronic hepatitis C patients. Approximately8321participants from several countries were included in this analysis. Six studies on serum vitamin D status and the severity of liver fibrosis were included in this meta-analysis. ORs with95%CIs were extracted from four studies and the pooled ORs were0.866(95%CI,0.649to1.157). The means with SDs were extracted from three studies and the pooled means were-0.487(95%CI,-0.659to-0.315). There was statistically significant heterogeneity among the mean data extracted studies (P=0.029; I2=71.8%) but not among the OR data extracted studies (P=0.061; I2=55.6%). Finally, results from the mean data extracted studies suggest that lower serum vitamin D is a risk factor for severity of liver fibrosis in chronic hepatitis C patients. However, there is no conclusive evidence on this association because of inconsistencies between the OR data extracted studies and the mean data extracted studies. |
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